/*
 * jerror.c
 *
 * Copyright (C) 1991-1994, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains simple error-reporting and trace-message routines.
 * These are suitable for Unix-like systems and others where writing to
 * stderr is the right thing to do.  Many applications will want to replace
 * some or all of these routines.
 *
 * These routines are used by both the compression and decompression code.
 */

/* this is not a core library module, so it doesn't define JPEG_INTERNALS */

#include "jinclude.h"
#include "jpeglib.h"
#include "jversion.h"
#include "jerror.h"

extern void jpg_Error( const char * fmt, ... );
extern void jpg_Printf( const char * fmt, ... );

#ifndef EXIT_FAILURE        /* define exit() codes if not provided */
#define EXIT_FAILURE  1
#endif


/*
 * Create the message string table.
 * We do this from the master message list in jerror.h by re-reading
 * jerror.h with a suitable definition for macro JMESSAGE.
 * The message table is made an external symbol just in case any applications
 * want to refer to it directly.
 */

#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jpeg_std_message_table  jMsgTable
#endif

#define JMESSAGE( code, string )   string,

const char * const jpeg_std_message_table[] = {
#include "jerror.h"
    NULL
};


/*
 * Error exit handler: must not return to caller.
 *
 * Applications may override this if they want to get control back after
 * an error.  Typically one would longjmp somewhere instead of exiting.
 * The setjmp buffer can be made a private field within an expanded error
 * handler object.  Note that the info needed to generate an error message
 * is stored in the error object, so you can generate the message now or
 * later, at your convenience.
 * You should make sure that the JPEG object is cleaned up (with jpeg_abort
 * or jpeg_destroy) at some point.
 */

METHODDEF void
error_exit( j_common_ptr cinfo ) {
    char buffer[JMSG_LENGTH_MAX];

    /* Create the message */
    ( *cinfo->err->format_message )( cinfo, buffer );

    /* Let the memory manager delete any temp files before we die */
    jpeg_destroy( cinfo );

    jpg_Error( "%s\n", buffer );
}


/*
 * Actual output of an error or trace message.
 * Applications may override this method to send JPEG messages somewhere
 * other than stderr.
 */

METHODDEF void
output_message( j_common_ptr cinfo ) {
    char buffer[JMSG_LENGTH_MAX];

    /* Create the message */
    ( *cinfo->err->format_message )( cinfo, buffer );

    /* Send it to stderr, adding a newline */
    jpg_Printf( "%s\n", buffer );
}


/*
 * Decide whether to emit a trace or warning message.
 * msg_level is one of:
 *   -1: recoverable corrupt-data warning, may want to abort.
 *    0: important advisory messages (always display to user).
 *    1: first level of tracing detail.
 *    2,3,...: successively more detailed tracing messages.
 * An application might override this method if it wanted to abort on warnings
 * or change the policy about which messages to display.
 */

METHODDEF void
emit_message( j_common_ptr cinfo, int msg_level ) {
    struct jpeg_error_mgr * err = cinfo->err;

    if ( msg_level < 0 ) {
        /* It's a warning message.  Since corrupt files may generate many warnings,
         * the policy implemented here is to show only the first warning,
         * unless trace_level >= 3.
         */
        if ( ( err->num_warnings == 0 ) || ( err->trace_level >= 3 ) ) {
            ( *err->output_message )( cinfo );
        }
        /* Always count warnings in num_warnings. */
        err->num_warnings++;
    } else {
        /* It's a trace message.  Show it if trace_level >= msg_level. */
        if ( err->trace_level >= msg_level ) {
            ( *err->output_message )( cinfo );
        }
    }
}


/*
 * Format a message string for the most recent JPEG error or message.
 * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
 * characters.  Note that no '\n' character is added to the string.
 * Few applications should need to override this method.
 */

METHODDEF void
format_message( j_common_ptr cinfo, char * buffer ) {
    struct jpeg_error_mgr * err = cinfo->err;
    int msg_code = err->msg_code;
    const char * msgtext = NULL;
    const char * msgptr;
    char ch;
    boolean isstring;

    /* Look up message string in proper table */
    if ( ( msg_code > 0 ) && ( msg_code <= err->last_jpeg_message ) ) {
        msgtext = err->jpeg_message_table[msg_code];
    } else if ( err->addon_message_table != NULL &&
                msg_code >= err->first_addon_message &&
                msg_code <= err->last_addon_message ) {
        msgtext = err->addon_message_table[msg_code - err->first_addon_message];
    }

    /* Defend against bogus message number */
    if ( msgtext == NULL ) {
        err->msg_parm.i[0] = msg_code;
        msgtext = err->jpeg_message_table[0];
    }

    /* Check for string parameter, as indicated by %s in the message text */
    isstring = FALSE;
    msgptr = msgtext;
    while ( ( ch = *msgptr++ ) != '\0' ) {
        if ( ch == '%' ) {
            if ( *msgptr == 's' ) {
                isstring = TRUE;
            }
            break;
        }
    }

    /* Format the message into the passed buffer */
    if ( isstring ) {
        sprintf( buffer, msgtext, err->msg_parm.s );
    } else {
        sprintf( buffer, msgtext,
                 err->msg_parm.i[0], err->msg_parm.i[1],
                 err->msg_parm.i[2], err->msg_parm.i[3],
                 err->msg_parm.i[4], err->msg_parm.i[5],
                 err->msg_parm.i[6], err->msg_parm.i[7] );
    }
}


/*
 * Reset error state variables at start of a new image.
 * This is called during compression startup to reset trace/error
 * processing to default state, without losing any application-specific
 * method pointers.  An application might possibly want to override
 * this method if it has additional error processing state.
 */

METHODDEF void
reset_error_mgr( j_common_ptr cinfo ) {
    cinfo->err->num_warnings = 0;
    /* trace_level is not reset since it is an application-supplied parameter */
    cinfo->err->msg_code = 0;/* may be useful as a flag for "no error" */
}


/*
 * Fill in the standard error-handling methods in a jpeg_error_mgr object.
 * Typical call is:
 *	struct jpeg_compress_struct cinfo;
 *	struct jpeg_error_mgr err;
 *
 *	cinfo.err = jpeg_std_error(&err);
 * after which the application may override some of the methods.
 */

GLOBAL struct jpeg_error_mgr *
jpeg_std_error( struct jpeg_error_mgr * err ) {
    err->error_exit = error_exit;
    err->emit_message = emit_message;
    err->output_message = output_message;
    err->format_message = format_message;
    err->reset_error_mgr = reset_error_mgr;

    err->trace_level = 0;   /* default = no tracing */
    err->num_warnings = 0;  /* no warnings emitted yet */
    err->msg_code = 0;      /* may be useful as a flag for "no error" */

    /* Initialize message table pointers */
    err->jpeg_message_table = jpeg_std_message_table;
    err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;

    err->addon_message_table = NULL;
    err->first_addon_message = 0;/* for safety */
    err->last_addon_message = 0;

    return err;
}
